Electrically driven, retractable rudder propeller including a step-down gear unit

ABSTRACT

A driving device for a ship is described, including a rudder propeller with a propeller shaft and with a vertical shaft which drives the propeller shaft via an angular gear unit and which is rotatable and driven by an electric driving motor, and including a lifting device for moving the rudder propeller between a retracted position within the ship and a deployed operating position outside the ship.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to PCT Application No. PCT/EP2013/057592 filed Apr. 11, 2013, which claims priority to German Patent Application No. 102012103814.7 filed May 2, 2012, each of which are incorporated herein by reference in their entirety.

FIELD

A driving device for a ship is described, including a rudder propeller with a propeller shaft and with a vertical shaft which drives the propeller shaft via an angular gear unit and which is rotatable and driven by an electric driving motor, and including a lifting device for moving the rudder propeller between a retracted position within the ship and a deployed operating position outside the ship.

BACKGROUND

Driving devices of the above-mentioned type are known whereby the rudder propeller due to its rotation around the vertical axis provides a high maneuverability to the similarly equipped ship. In addition to the fixed installations, in which the drive motor within the hull and the rudder propeller are always positioned outside of the hull, also deployed positions of the rudder propellers are used where the rudder propeller, when not in use, is located within the hull and if necessary, such as maneuvering within a port or at sea, e.g. in the dynamic positioning operation is deployed out of the ship's hull to a position outside the ship.

For currently known driving devices of the kind referred to above with a rudder propeller, the power is typically transferred from a horizontally positioned drive motor to the vertical shaft and again from there to the propeller shaft positioned essentially horizontally. This requires a change of drive direction of the power flow in increments of 90 degrees, which is commonly refer to as a Z-drive, or the drive motor drives the vertical shaft directly, so that only a change of drive direction of 90 degrees is necessary on the essentially horizontally positioned propeller shaft, commonly referred to as a L-drive.

The drive system of deployable rudder propellers using a lifting device is usually done by electric drive motors directly coupled to the vertical shaft in the form of an L-drive or else by diesel or electric drive motors coupled horizontally with an upstream cut-out clutch using an above-water gear unit in the form of a Z-drive. In particular for large plants the overall height plays an important role, since the overall height of the existing space in a ship engine room can be very limited. Due to the required retracted and deployed positions of the rudder propeller a space of approximately twice that of the portion remaining under water of the driving device plus space for the portion above water and the required substructure, portals and the units for the lifting equipment is necessary on the ship. Regardless of the type of the drive as L- or Z-drive, the drive motor is always used as one of the highest points of the propelling device and significantly influences the space requirements or space of the propelling device. Provided that, as more recently required more and more, the hybrid operation is carried out with parallel or alternate driving by electrical and diesel engines, the amount of space required increases, which is an undesirable high constructive effort.

In addition, the use of known electric drive motors require driving devices with mid-range speed and high torque, in order to design the speed range in approximately the same speed range of a diesel engine. Such electric motors having high torque and mid-range speeds, on the other hand, are very heavy and have a high volume space, connected with the already mentioned disadvantages for the required space.

BRIEF DESCRIPTION

In an embodiment, a driving or propelling device of the above-mentioned type, which avoids the disadvantages of the prior art is provided.

In an embodiment, a driving device for a ship, including a rudder propeller with a propeller shaft and with a vertical shaft which drives the propeller shaft via an angular gear unit and which is rotatable and driven by an electric driving motor, and including a lifting device for moving the rudder propeller between a retracted position within the ship and a deployed operating position outside the ship.

Optimized designs and further improvements are also described.

According to an embodiment, a step-down gear positioned between the electric drive motor and the vertical shaft is provided.

In an embodiment, the step-down gear will make it possible to use, instead of more difficult, more expensive and more voluminous electric motors, a much smaller and lighter but fast running electric motor utilizing a mid-range speed and high torque. As the electrical driving motor, the high speed of which, provided by the specified step-down gear unit, is geared down to a suitable speed range for the drive torque of the vertical shaft with a simultaneous torque multiplication. According to an embodiment, the step-down gear unit performs comparatively better when arranged horizontally, in particular as a spur gear transmission with a vertically arranged spur gear axis. In this way, it is possible to position the electric drive motor with its drive shaft axially parallel to the vertical shaft.

According to an embodiment, the electric drive motor is positioned below the step-down gear unit, so that the power flow from the vertically positioned drive shaft of the electric motor of the step-down gear is redirected twice, or two times, in a 90 degree direction on the vertical shaft, i.e. it is a drive in the form of a reverse U shape. In this way, the electric drive motor is no longer positioned as the most extreme point of the propelling device, but can also be arranged next to the vertical shaft and below the step-down gear unit, so that there is a significant reduction in space requirement. According to an embodiment, utilization of a small and fast-running electric motor will further reduce this requirement.

Moreover, providing a connection on the vertical shaft to a gear unit above a water level, which in the traditional design forms a connection over a mechanical clutch to a diesel engine, allows implementation of a space-saving hybrid drive. In this case, a connection to a vertical electric motor according to an embodiment shall be implemented over a rear sprocket of the step-down gear unit used as a spur gear system, which is mounted, for example, in addition to the gear unit positioned above the water level, on the control gear plate. The rear sprocket can have an effect on the wheel of the spur gear transmission in the form of an internal ring gear or in a parallel configuration, so that the necessary gear ratio reduction for the preferred fast rotating electric motor can be established comfortably.

According to an embodiment, the electric drive motor and the step-down gear unit move together with the rudder propeller by means of the lifting device.

According to a further embodiment, the electric drive motor is positioned fixed inside the ship, while the step-down gear unit moves, using the lifting equipment, together with the rudder propeller and a clutch is provided between the drive motor and the step-down gear unit with which the drive motor next to the rudder propeller moves into operational position and can be coupled up with the step-down gear unit.

Provided that the vertical shaft of the driving device according to an embodiment is operable in addition to the electric drive motor with a further drive motor, is driven for example in the context of a hybrid system with an internal combustion engine, the electric drive motor, when not in use, can also be operated as a generator, to be used for energy generation.

BRIEF DESCRIPTION OF THE FIGURES

The invention is described below and explained with additional specificity and detail using the accompanying drawing representative of the sample in which:

FIG. 1 is a cross-sectional side view of a driving device according to an embodiment.

DETAILED DESCRIPTION

The above-referenced drawing is representative of an embodiment, and shows the only diagram in a highly schematic representation in which a driving device 1 for a ship including a rudder propeller 10 in a known position can be moved by means of a lifting device in the direction of the arrow H vertically along its center axis M in the casing 16 positioned in the ship hull either into the operating position shown in the drawing in which the rudder propeller 10 is located outside of the hull or when not in use, to be retracted completely into the casing 16 within the hull.

The drive of the rudder propeller 10 is carried out, in an already known manner, utilizing a vertical shaft 11 stretching along the center axis M, which carries an angular gear at its lower end, and which is used as a component of an angular gear system 100 to drive the horizontal propeller shaft 101 and thus finally the propeller 102 mounted at the end of the propeller shaft 101.

The vertical shaft 11 is guided within a tube 14, which leads to a control gear plate 13, with which the entire unit can be slewed at 360 degrees around the center axis M, not described in detail, so that the ship can be steered by means of the rudder propeller 10.

Above the control gear plate 13 and to the extent of the above represented example, at the highest point of the driving device, there is a step-down gear unit 15 in the form of a horizontally arranged spur gear system with spur gears 15 a, 15 b, which is driven by a highly compact and fast-running electric drive motor 12. The electric drive motor 12 is for this purpose a drive shaft extending axially parallel to the vertical shaft 120 the central axis of which is identified with A and which drives the spur gear 15 a which is smaller in radius which in turn ensures the operation of the spur gear 15 b with larger diameter which is mounted on the vertical shaft 11. So far, the speed of the electric motor 12 in overdrive is slowed down, namely to a speed suitable for use at the vertical shaft 11 of a rudder propeller, while at the same time the effective torque of the drive motor 12 is increased accordingly.

Decisive for the particularly small footprint of the driving device is that with this arrangement of a vertically running drive shaft of the electric motor, the horizontally tapered step-down gear unit and then again vertically running vertical shaft 11 of the power flow is positioned in the form of an inverted U shape and the electric drive motor 12 can be positioned below the control gear plate 13 and below the step-down gear unit 15 in a space so far not used in such deployable rudder propellers. Moreover, as a result of the use of a step-down gear unit 15 a particularly fast rotating and thus lighter and smaller electrical drive motor 12 may be used for a further reduction of the footprint. 

1. A driving device for a ship, comprising: a rudder propeller comprising a propeller shaft and a vertical shaft which drives the propeller shaft via an angular gear unit and which is rotatable and driven by an electric driving motor; a lifting device for moving the rudder propeller between a retracted position within the ship and a deployed operating position outside the ship; and a step-down gear unit is provided between the electric driving motor and the vertical shaft.
 2. The driving device of claim 1, wherein the step-down gear unit is configured as a spur gear with a vertical spur gear axis.
 3. The driving device of claim 1, wherein the electric driving motor drives a drive shaft which is fitted axially parallel to the vertical shaft.
 4. The driving device of claim 3, wherein the electric driving motor is fitted below the step-down gear unit.
 5. The driving device of claim 1, wherein the electric driving motor and the step-down gear unit can be moved by the lifting device together with the rudder propeller.
 6. The driving device of claim 1, wherein the electric driving motor and the step-down gear unit are positioned inside the ship.
 7. The driving device of claim 1, wherein the electric driving motor is positioned fixed inside the ship, while the step-down gear unit moves, using the lifting device, together with the rudder propeller and a clutch is provided between the electric driving motor and the step-down gear unit with which the electric driving motor next to the rudder propeller moved into operational position can be coupled up with the step-down gear unit.
 8. The driving device of claim 1, wherein the vertical shaft next to the electric driving motor can be driven with an additional driving motor.
 9. The driving device of claim 1, wherein the electric driving motor can be operated as a generator. 